25 years on, Tiananmen barely known to China youth

A Chinese paramilitary security force officer stands under a portrait of the late Mao Zedong as others march passed outside the Forbidden City at Tiananmen Square on June 2, 2014 in Beijing, China. Twenty-five years ago on June 4, 1989, Chinese troops cracked-down on pro-democracy protesters leaving hundreds, perhaps thousands, dead and injured.